Minor docs and examples updates

Author: rudyryk

docs/peewee_async/tornado.rst

@@ -9,129 +9,17 @@ The complete working example is provided below. And here are some general notes:
 
 1. **Be aware of current asyncio event loop!**
 
-  In the provided example we use the default event loop everywhere, and that's OK. But if you see your application got silently stuck, that's most probably that some task is started on different loop and will never complete as long as that loop is not running.
+  In the provided example we use the default event loop everywhere, and that's OK. But if you see your application got silently stuck, that's most probably that some task is started on the different loop and will never complete as long as that loop is not running.
 
 2. Tornado request handlers **does not** start asyncio tasks by default.
 
-  The ``CreateHandler`` demostrates that, ``current_task()`` returns ``None`` until taks is run explicitly.
+  The ``CreateHandler`` demostrates that, ``current_task()`` returns ``None`` until task is run explicitly.
 
 3. Transactions **must** run within task context.
 
   All transaction operations have to be done within task. So if you need to run a transaction from Tornado handler, you have to wrap your call into task with ``create_task()`` or ``ensure_future()``.
 
-  **Also note:** if you spawn an extra task during transaction, it will run outside of transaction.
+  **Also note:** if you spawn an extra task during a transaction, it will run outside of that transaction.
 
-.. code-block:: python
-
-    import tornado.web
-    import logging
-    import peewee
-    import asyncio
-    import peewee_async
-
-    # Set up database and manager
-    database = peewee_async.PooledPostgresqlDatabase('test')
-
-    # Define model
-    class TestNameModel(peewee.Model):
-        name = peewee.CharField()
-        class Meta:
-            database = database
-
-        def __str__(self):
-            return self.name
-
-    # Create table, add some instances
-    TestNameModel.create_table(True)
-    TestNameModel.get_or_create(id=1, defaults={'name': "TestNameModel id=1"})
-    TestNameModel.get_or_create(id=2, defaults={'name': "TestNameModel id=2"})
-    TestNameModel.get_or_create(id=3, defaults={'name': "TestNameModel id=3"})
-    database.close()
-
-    # Set up Tornado application on asyncio
-    from tornado.platform.asyncio import AsyncIOMainLoop
-    AsyncIOMainLoop().install()
-    app = tornado.web.Application(debug=True)
-    app.listen(port=8888)
-    app.objects = peewee_async.Manager(database)
-
-    # Add handlers
-    class RootHandler(tornado.web.RequestHandler):
-        """Accepts GET and POST methods.
-
-        POST: create new instance, `name` argument is required
-        GET: get instance by id, `id` argument is required
-        """
-        async def post(self):
-            name = self.get_argument('name')
-            obj = await self.application.objects.create(TestNameModel, name=name)
-            self.write({
-                'id': obj.id,
-                'name': obj.name
-            })
-      
-        async def get(self):
-            obj_id = self.get_argument('id', None)
-
-            if not obj_id:
-                self.write("Please provide the 'id' query argument, i.e. ?id=1")
-                return
-
-            try:
-                obj = await self.application.objects.get(TestNameModel, id=obj_id)
-                self.write({
-                    'id': obj.id,
-                    'name': obj.name,
-                })
-            except TestNameModel.DoesNotExist:
-                raise tornado.web.HTTPError(404, "Object not found!")
-
-    class CreateHandler(tornado.web.RequestHandler):
-        async def get(self):
-            loop = asyncio.get_event_loop()
-            task1 = asyncio.Task.current_task()
-            task2 = loop.create_task(self.get_or_create())
-            obj = await task2
-            self.write({
-                'task1': task1 and id(task1),
-                'task2': task2 and id(task2),
-                'obj': str(obj),
-                'text': "'task1' should be null, "
-                        "'task2' should be not null, "
-                        "'obj' should be newly created object",
-            })
-
-        async def get_or_create(self):
-            obj_id = self.get_argument('id', None)
-            async with self.application.objects.atomic():
-                obj, created = await self.application.objects.get_or_create(
-                    TestNameModel, id=obj_id,
-                    defaults={'name': "TestNameModel id=%s" % obj_id})
-                return obj
-
-    app.add_handlers('', [
-        (r"/", RootHandler),
-        (r"/create", CreateHandler),
-    ])
-
-    # Setup verbose logging
-    log = logging.getLogger('')
-    log.addHandler(logging.StreamHandler())
-    log.setLevel(logging.DEBUG)
-
-    # Run loop
-    print("""Run application server http://127.0.0.1:8888
-
-        Try GET urls:
-        http://127.0.0.1:8888?id=1
-        http://127.0.0.1:8888/create?id=100
-
-        Try POST with name=<some text> data:
-        http://127.0.0.1:8888
-
-    ^C to stop server""")
-    loop = asyncio.get_event_loop()
-    try:
-        loop.run_forever()
-    except KeyboardInterrupt:
-        print(" server stopped")
+.. literalinclude:: ../../examples/tornado_sample.py
+  :start-after: # Start example

examples/tornado_sample.py

@@ -12,6 +12,7 @@
 Copyright (c) 2016, Alexey Kinëv <[email protected]>
 
 """
+# Start example [marker for docs]
 import tornado.web
 import logging
 import peewee
@@ -78,7 +79,7 @@ async def get(self):
 class CreateHandler(tornado.web.RequestHandler):
     async def get(self):
         loop = asyncio.get_event_loop()
-        task1 = asyncio.Task.current_task()
+        task1 = asyncio.Task.current_task() # Just to demonstrate it's None
         task2 = loop.create_task(self.get_or_create())
         obj = await task2
         self.write({